Befogging the brainBMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6930.725a (Published 12 March 1994) Cite this as: BMJ 1994;308:725
- B Dixon
I've just returned from a round trip on the M25 around London, a total distance of 100 miles (160 km) or so from junction 16 to junction 28, which I negotiate at least once each week. It was foggy, exceedingly foggy in places, while elsewhere there were patches of mere mist and several areas with clear air.
The motorway is well served with fog warning lights, and someone somewhere was obviously busy at the controls. The problem was this. The illumination of the signs bore only the most random relation to the density of the fog. There was warning after warning in regions of sunshine and clarity, yet nothing whatever amid murky areas with the poorest visibility of all. Occasionally the fog happened …